scholarly journals Universal structure motifs in biominerals: a lesson from nature for the efficient design of bioinspired functional materials

2017 ◽  
Vol 7 (4) ◽  
pp. 20160120 ◽  
Author(s):  
Joe Harris ◽  
Corinna F. Böhm ◽  
Stephan E. Wolf
Keyword(s):  
Composite Structure ◽  
Functional Materials ◽  
Structural Diversity ◽  
Emergent Properties ◽  
Efficient Design ◽  
Link Type ◽  
Macro Scale ◽  
Scale Properties ◽  
Universal Structure ◽  
Design Motifs

Biominerals are typically indispensable structures for their host organism in which they serve varying functions, such as mechanical support and protection, mineral storage, detoxification site, or as a sensor or optical guide. In this perspective article, we highlight the occurrence of both structural diversity and uniformity within these biogenic ceramics. For the first time, we demonstrate that the universality–diversity paradigm, which was initially introduced for proteins by Buehler et al . (Cranford & Buehler 2012 Biomateriomics ; Cranford et al. 2013 Adv. Mater. 25 , 802–824 ( doi:10.1002/adma.201202553 ); Ackbarow & Buehler 2008 J. Comput. Theor. Nanosci. 5 , 1193–1204 ( doi:10.1166/jctn.2008.001 ); Buehler & Yung 2009 Nat. Mater. 8 , 175–188 (doi:10.1038/nmat2387)), is also valid in the realm of biomineralization. A nanogranular composite structure is shared by most biominerals which rests on a common, non-classical crystal growth mechanism. The nanogranular composite structure affects various properties of the macroscale biogenic ceramic, a phenomenon we attribute to emergence. Emergence, in turn, is typical for hierarchically organized materials. This is a clear call to renew comparative studies of even distantly related biomineralizing organisms to identify further universal design motifs and their associated emergent properties. Such universal motifs with emergent macro-scale properties may represent an unparalleled toolbox for the efficient design of bioinspired functional materials.

scholarly journals Identification of new silk-like protein from B. magister and development of functional materials based on it

2021 ◽  
Vol 2086 (1) ◽  
pp. 012123
Author(s):  
A A Vronskaia ◽  
A D Mikushina ◽  
I E Eliseev
Keyword(s):  
Thin Films ◽  
Drug Delivery ◽  
Tandem Repeat ◽  
Composite Structure ◽  
Textile Industry ◽  
Functional Materials ◽  
Repeat Proteins ◽  
Tandem Repeat Proteins ◽  
New Protein

Abstract Tandem repeat proteins have composite structure and unique properties, which allow them to be used in multiple fields, such as soft photonics, drug delivery and textile industry. The recent discovery of squid ring teeth (SRT) proteins have expanded the existing repertoire of repetitive polypeptides. We chose previously unexplored squid B. magister for our research, isolated and analyzed a new protein forming its ring teeth and hooks, and amplified the corresponding gene. Finally, we used this new isolated SRT protein to fabricate transparent thin films and microspheres.

Comparing Micro- and Macro-Level Rheological Properties of Polymeric and Reclaimed Asphalt Pavement-Modified Asphalt Binders

2021 ◽  
pp. 036119812110288
Author(s):  
Tandra Bagchi ◽  
Zahid Hossain ◽  
Mohammed Ziaur Rahaman ◽  
Gaylon Baumgardner
Keyword(s):  
Mechanical Properties ◽  
Scale Effects ◽  
Asphalt Pavement ◽  
Linear Trend ◽  
Asphalt Binders ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Multi Scale ◽  
Macro Scale ◽  
Scale Properties

Multi-scale evaluation of the rheological and mechanical properties of asphalt binder has substantial importance in understanding the binder’s micro- and macro-scale properties. This study compares the macro- and micro-scale mechanistic properties of asphalt binders. Test samples used in this study include performance grade binders (PG 64-22) from two different sources along with their modified counterparts. The modifiers include polyphosphoric acid (PPA), styrene-butadiene-styrene (SBS), a combination of SBS and PPA, and reclaimed asphalt pavement. To achieve the goal of this study, atomic force microscope technology was utilized to estimate the asphalt binder’s micro-mechanical properties (e.g., Derjaguin, Muller, Toropov modulus and deformation). On the other hand, data on the macro-scale properties—such as rutting factor (G*/sinδ), consistency and penetration—of the selected binders were analyzed and compared with the aforementioned micro-level properties. The comparative analyses indicated that the micro-mechanical properties of asphalt binders followed a linear trend with the macro-scale properties. The findings of this study are expected to help researchers and pavement professionals in modeling asphalt materials when multi-scale effects are deemed to be necessary.

scholarly journals Smart City Governance and Children’s Agency: An Assessment of the Green Infrastructure Impact on Children’s Activities in Cagliari (Italy) with the Tool “Opportunities for Children in Urban Spaces (OCUS)”

2019 ◽  
Vol 11 (18) ◽  
pp. 4848 ◽  
Author(s):  
Chiara Garau ◽  
Alfonso Annunziata
Keyword(s):  
Urban Planning ◽  
Green Infrastructure ◽  
Smart City ◽  
Urban Areas ◽  
Resource Depletion ◽  
Urban Spaces ◽  
Urban Green Spaces ◽  
Synthetic Index ◽  
Macro Scale ◽  
Scale Properties

The increases in urbanization, pollution, resource depletion, and climate change underline the need for urban planning policies that incorporate blue–green infrastructure (BGI) and ecosystem services. This paper proposes a framework for assessing BGI’s effect on children’s outdoor activities. This effect, called meaningful usefulness, is a central issue due to the influence of experiences with nature on children’s development and the global trend of concentration of children in urban areas. Based on the concept of affordance, the methodology formalizes meaningful usefulness in terms of an index of usefulness of individual settings (IUIS) and a synthetic index of usefulness of BGI in a specific area (ISGI). These are determined via an audit protocol, Opportunities for Children in Urban Spaces (OCUS), which incorporates a set of indicators measuring micro-scale properties of individual places and contextual macro-scale factors. The methodology is applied to BGI components in Cagliari, Sardinia, Italy, which was selected for its superior density of urban green spaces. The application of the OCUS tool confirms its usefulness for investigating functional affordances incorporated into the trans-scalar structures of BGIs. The analytic protocol further contributes to the implementation of urban planning strategies within the smart city paradigm.

Wood cell wall ultrastructure The key to understanding wood properties and behaviour

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 645-672
Author(s):  
Lloyd A. Donaldson
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Wood Cell Wall ◽  
Imaging Techniques ◽  
Wood Properties ◽  
Reaction Wood ◽  
Cell Wall Ultrastructure ◽  
Macro Scale ◽  
Wall Ultrastructure ◽  
Scale Properties

ABSTRACTIn the last 100 years, major advances have been made in understanding wood cell wall ultrastructure in tracheids, fibres, vessels and parenchyma and its relationship with xylem function and wood properties. This review will focus on how the development of imaging techniques and their application to wood cell walls has led to an understanding of cell wall organisation and the relationship between micro and macro scale properties in wood and wood-based materials. Topics such as wood formation, wood chemistry and reaction wood have recently been reviewed elsewhere and are considered only briefly in this review. Two features of wood cell walls have dominated the literature; orientation and layering of cellulose which determines the longitudinal stiffness of wood, and the distribution (topochemistry) of lignin which determines compression strength and pulping properties.

Characterisation of the temperature-dependent M1 to R phase transition in W-doped VO2 nanorod aggregates by Rietveld refinement and theoretical modelling

2020 ◽  
Vol 22 (15) ◽  
pp. 7984-7994
Author(s):  
Lei Miao ◽  
Ying Peng ◽  
Dianhui Wang ◽  
Jihui Liang ◽  
Chaohao Hu ◽  
...  
Keyword(s):  
Rietveld Refinement ◽  
First Principles ◽  
Atomic Scale ◽  
Theoretical Modelling ◽  
First Principles Calculations ◽  
Temperature Dependent ◽  
Macro Scale ◽  
Scale Properties ◽  
W Doping ◽  
Synchrotron Xrd

Synchrotron XRD Rietveld refinement is combined with first-principles calculations to probe the effect of W doping on the IMT mechanism in VO2 nanorods, providing insights into the connection between atomic-scale phenomena and macro-scale properties.

UHPC and FRC in Severe Environmental Conditions

2016 ◽  
Vol 711 ◽  
pp. 412-419 ◽  
Author(s):  
Stanislav Rehacek ◽  
Ivo Simunek ◽  
David Citek ◽  
Jiří Kolísko
Keyword(s):  
Environmental Conditions ◽  
Cement Composite ◽  
Joint Effect ◽  
Experimental Program ◽  
Cement Composites ◽  
Structure And Properties ◽  
Physical Chemical ◽  
Chemical Agents ◽  
Macro Scale ◽  
Scale Properties

Structure and properties of cement composite are time-varying characteristics, depending among others on environmental conditions. The key idea is a struggle for complex research of joint effect of physical, chemical and dynamic loads on the internal structure [1] of cement composite and understanding the correlation between changes in microstructure and macro-scale properties [2, 3]. During the experimental program, specimens will be exposed to combined influence of freeze-thaw cycles [4,5,6], aggressive chemical agents [7] and dynamic loading [8]. The aim is to create a theoretical basis for design of effective cement composites meant to be used in severe environmental conditions.

scholarly journals Structural diversity across arbuscular mycorrhizal, ectomycorrhizal, and endophytic plant—fungus networks

2018 ◽  
Author(s):  
Hirokazu Toju ◽  
Hirotoshi Sato ◽  
Satoshi Yamamoto ◽  
Akifumi S. Tanabe
Keyword(s):  
Network Architecture ◽  
High Throughput Sequencing ◽  
Latitudinal Gradient ◽  
Terrestrial Ecosystem ◽  
Arbuscular Mycorrhizal ◽  
Structural Diversity ◽  
Terrestrial Ecosystems ◽  
Ecosystem Dynamics ◽  
Plant Seed ◽  
Scale Properties

AbstractBackgroundBelow-ground linkage between plant and fungal communities is one of the major drivers of terrestrial ecosystem dynamics. However, we still have limited knowledge of how such plant–fungus associations vary in their community-scale properties depending on fungal functional groups and geographic locations.MethodsBased on high-throughput sequencing of root-associated fungi in eight forests along the Japanese Archipelago, we performed a comparative analysis of arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic associations across a latitudinal gradient from cool-temperate to subtropical regions.ResultsIn most of the plant–fungus networks analyzed, host–symbiont associations were significantly specialized but lacked “nested” architecture, which has been commonly reported in plant–pollinator and plant–seed disperser networks. Meanwhile, the structure of arbuscular mycorrhizal networks was differentiated from that of ectomycorrhizal and saprotrophic/endophytic networks, characterized by high connectance. Our data also suggested that geographic factors affected the organization of plant–fungus network structure. For example, the southernmost subtropical site analyzed in this study displayed lower network-level specificity of host–symbiont associations and higher (but still low) nestedness than northern localities.ConclusionsOur comparative analyses suggest that arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic plant–fungus associations often lack nested network architecture, while those associations can vary, to some extent, in their community-scale properties along a latitudinal gradient. Overall, this study provides a basis for future studies that will examine how different types of plant–fungus associations collectively structure terrestrial ecosystems.

scholarly journals Insights into evolution and coexistence of the colibactin- and yersiniabactin secondary metabolite determinants in enterobacterial populations

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Haleluya Wami ◽  
Alexander Wallenstein ◽  
Daniel Sauer ◽  
Monika Stoll ◽  
Rudolf von Bünau ◽  
...  
Keyword(s):  
Type Species ◽  
Structural Diversity ◽  
Eukaryotic Cell ◽  
Genomic Region ◽  
Content Type ◽  
Integrative And Conjugative Elements ◽  
Link Type ◽  
Bacterial Genetic ◽  
Species Specific

The bacterial genotoxin colibactin interferes with the eukaryotic cell cycle by causing dsDNA breaks. It has been linked to bacterially induced colorectal cancer in humans. Colibactin is encoded by a 54 kb genomic region in Enterobacteriaceae . The colibactin genes commonly co-occur with the yersiniabactin biosynthetic determinant. Investigating the prevalence and sequence diversity of the colibactin determinant and its linkage to the yersiniabactin operon in prokaryotic genomes, we discovered mainly species-specific lineages of the colibactin determinant and classified three main structural settings of the colibactin–yersiniabactin genomic region in Enterobacteriaceae . The colibactin gene cluster has a similar but not identical evolutionary track to that of the yersiniabactin operon. Both determinants could have been acquired on several occasions and/or exchanged independently between enterobacteria by horizontal gene transfer. Integrative and conjugative elements play(ed) a central role in the evolution and structural diversity of the colibactin–yersiniabactin genomic region. Addition of an activating and regulating module (clbAR) to the biosynthesis and transport module (clbB-S) represents the most recent step in the evolution of the colibactin determinant. In a first attempt to correlate colibactin expression with individual lineages of colibactin determinants and different bacterial genetic backgrounds, we compared colibactin expression of selected enterobacterial isolates in vitro. Colibactin production in the tested Klebsiella species and Citrobacter koseri strains was more homogeneous and generally higher than that in most of the Escherichia coli isolates studied. Our results improve the understanding of the diversity of colibactin determinants and its expression level, and may contribute to risk assessment of colibactin-producing enterobacteria.

Integrating an Analytical Uncertainty Quantification Approach to Multi-Scale Modeling of Nanocomposites

2019 ◽  
pp. 1-22
Author(s):  
Pinar Acar
Keyword(s):  
Uncertainty Quantification ◽  
Uncertainty Propagation ◽  
Epoxy Nanocomposites ◽  
Linear Solution ◽  
Analytical Uncertainty ◽  
Multi Scale ◽  
Scale Modeling ◽  
Macro Scale ◽  
Multi Scale Modeling ◽  
Scale Properties

Abstract The present study addresses the integration of an analytical uncertainty quantification approach to multi-scale modeling of single-walled carbon nanotube (SWNT)-epoxy nanocomposites. The main highlight is the investigation of the stochasticity of nanotube orientations, and its effects on the homogenized properties. Even though the properties of SWNT-epoxy nanocomposites are well-studied in the literature, the natural stochasticity that arises from the nanotube orientations has not been observed. To understand the effects of the variability in SWNT orientations to material properties of interest, an analytical uncertainty quantification algorithm is utilized. The analytical scheme computes the propagation of the orientational uncertainty to the volume-averaged properties with a linear solution and uses the transformation of random variables principle to obtain the variations in non-linear properties. The results indicate that the uncertainty propagation affects the macro-scale properties, including stiffness, thermal expansion, thermal conductivity, and natural frequencies.

scholarly journals A Simulator for Large-Scale Parallel Computer Architectures

2010 ◽  
Vol 1 (2) ◽  
pp. 57-73 ◽  
Author(s):  
Curtis L. Janssen ◽  
Helgi Adalsteinsson ◽  
Scott Cranford ◽  
Joseph P. Kenny ◽  
Ali Pinar ◽  
...  
Keyword(s):  
Message Passing ◽  
Large Scale ◽  
Message Passing Interface ◽  
Parallel Execution ◽  
Parallel Computer ◽  
Coarse Grained ◽  
Efficient Design ◽  
Standard Format ◽  
Trace File ◽  
Macro Scale

Efficient design of hardware and software for large-scale parallel execution requires detailed understanding of the interactions between the application, computer, and network. The authors have developed a macro-scale simulator (SST/macro) that permits the coarse-grained study of distributed-memory applications. In the presented work, applications using the Message Passing Interface (MPI) are simulated; however, the simulator is designed to allow inclusion of other programming models. The simulator is driven from either a trace file or a skeleton application. Trace files can be either a standard format (Open Trace Format) or a more detailed custom format (DUMPI). The simulator architecture is modular, allowing it to easily be extended with additional network models, trace file formats, and more detailed processor models. This paper describes the design of the simulator, provides performance results, and presents studies showing how application performance is affected by machine characteristics.

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